Conventional optical switches are notoriously difficult to expand without re-engineering.
3D optical switches are typically built with two opposite arrays of beam steering elements where each element of a first array is able to point to any selected element of a second array. Optical characteristics of the beam steering elements impose limits on the working distance between the first and second arrays.
Beam steering elements are usually sufficiently spaced in an array to accommodate their respective motion. A given beam steering element will be limited in terms of its achievable swing for an acceptable level of stability and noise. Increasing the angle of the swing of a given beam steering element is not an effective option since it is likely to cause unwanted noise and instabilities.
One of the objectives of the present invention is to introduce an approach or a series of approaches which allow conventional switch building blocks to be used to increase the capacity of the switch without having to swing at excessive angles, without any significant loss, without having to incorporate higher performance lenses and without having to overall re-engineer the switch.
A particular objective of the present invention is to produce a switch which can be extended without having to incorporate large optical elements with a greater working distance and without having to build the steering arrangements so as to allow larger angles of swing to be performed.
Another particular objective of the present invention is to produce a switch which fulfils both a prior art switching function and simultaneously exploits the optical spaces between conventional optical paths in order to increase the switch's capacity without necessarily extending the working distance.